This application relates to the art of storing electrical energy and, more particularly, to storage of electrical energy for an extended period of time on a capacitor. The invention is particularly applicable for use in an automatic automobile leveling system and will be described with reference thereto. However, it will be appreciated that the invention has broader aspects and may be used in other environments where it is desired to store a useful charge on a capacitor for an extended period of time.
Automatic leveling systems for automobiles operate off the automobile electrical system when the ignition is turned on. When the weight of a large number of passengers and luggage is removed from an automobile after the ignition is turned off, the automatic leveling system is not operative and the automobile will assume an extreme out-of-level condition. This is frequently undesirable for aesthetic and other reasons. Therefore, it would be desirable to have the automatic leveling system operative after the ignition is turned off. However, bypassing the ignition switch and connecting the battery directly to the leveling system could discharge the battery to a point where it was no longer capable of starting the engine. For example, vandals or a high wind could cause nearly constant operation of the leveling system until the battery was seriously discharged. In addition, the vehicle could be parked with its bumper above or below an obstruction which would prevent movement of the vehicle to a balanced condition and the constant operation of the leveling system in attempting to balance the vehicle would soon discharge the battery. It would be desirable to have an arrangement whereby the automatic leveling system would be operative for a limited time after the ignition is turned off and to utilize this time at one or more random intervals over an extended storage period. This would protect the battery against severe discharge and provide for normal leveling of the unattended vehicle.